Draft gear



Feb. 1 1927,

L. T. CANFIELD DRAFT GEAR Filed April 28, 1926 2 Sheets-Sheet l 1 1927'I I... T. CANFIELD DRAFT GEAR Filed ADIil.28. 1926 2 Sheets-Sheet 2.Zizua 07 02.4455 Z Oa/UZaLd J9; flaw, MW W5 Patented Feb. 1, 1927.

own-: "STATES rArEN-r IoFFIcE.

' LEWIS 'r. ommnnor CHICAGO, rumors, nssrenon 'ro UNION DRAFT GEAR 00.,

' or cmcneo, ILLmoIs, A CORPORATION or DELAWARE. I

DRAM GEAR.

' Application filed April as, 926. Serial No. 105,140.

The invention relates to draft gears for' railway cars, its objectsbeing to secure high efficiency and simplicity of construction.

The invention consists in a structure such as ls'hereinafter describedand as illustrated in the accompanyingdrawings, in'which view of'thecenter .Fig. 1 is-a detail plan frame members of a car, with theimproved gear applied thereto, the gear being shown in central plansection, in release position;

' Figs. 2 and'3 are views inperspective of elements of the gear; Fig. 4:is a central plan section'of the gear under full compression; v

' Fig. 5 is a transverse section on the line 5-5 of Fig.4; and w Fig. 6is a central plan section of the gear, showing a modified form ofconstruction.

The center or. draft sills of a car areshown at 10, a pair of draft lugsat 11-11, and a pair of bufiing lugs at 12 -12. There is used inconnectionwith'the gear a pair of plate followers 13, 14 which cooperaterespectively with the draft and bufiing lugs. The

butt of a drawbaris shown at 15 and the yoke 'or drawbar extension whichencircles the gear is. represented at 16. All ofthese are a pluralityparts are of any preferred construction.

The gear comprlses a barrel 17 in the form of a heavy helical springformed of a coiled bar which is rectangular in cross-section,

- one of the faces of the bar forming the bore of the barrel. The endsof the barrel are seated against laterally. extending flanges as 18, 19,of a pair of wedge blocks 20, 20, which flanges bear against the innerfaces of the followers 13,14.

Cooperating with the wedge blocks 20, 20 of sector-shaped wedge shoesthe shoes of each set are three 21. As shown, extending through approxl-A mately 120, though a greater number may be employed if desired. Thewedge faces of the blocks 20 correspond in number to the shoes.' t

In the preferred form of construction each set. of wedge shoes isenclosedwithin a longitudinally divided sectional shell 22, one e ment23 of which is shown in perspective in Fig. 2 While these shells 'areshown as comprising two elements each, extending through 180, it isobvious that thefy may be composed of a greater number 0 sections ofcorrespondingly less circumferential extent. The shoes21 are providedwith longi- .sh ow lengtii full compression of the gear.

-tudinal extensions 24 projecting beyond the bases of the wedgingportions and bearing against and conforming to the inner surfaces oftheshells 22. "Helical springs as 25 react between the head or wedgeportions of the U shoes 21 and end walls 26 of the shells 22.

The inner ends or end. walls 26-of the two that it will [not interferewith the Normally the parts assume'the positions as shownin Fig. 1. Uponthe application of compressive forces either of draft or buff .one ofthe followers 13, 14 is advanced coinpressing the spring of which thebarrel 17 is constituted and forcing the wedge shoes 21 radially outwardagainst the walls of the shell elements, thus expanding the shells andforcing themv against the inner surface of the barrel. The shoes 21' arecarried forward by the advancing follower against the resistance of, thesprings 25, the shoes at the opposite end of the gear being advancedagainst the wedge block 20 with which they coop-' 'era-te and expandingtheshell by which they are enclosed. The shells .are carried forward bythe frictional engagement with them of the wedge shoes and against thefrictional resistance between them and theinner surface of the barrel.

to permit the use of a bolt of such shells 22 are always in contact andobviously The parts are soproportioned that when the gear iscompletelycompressed they assume the relative positions as shown in Fig. 4, thespring constituting the barrel 17 being completely closed and theends'of' the shells being in contact with the flanges as 17, 18' of thewedge blocks. .Releasejis ef-" fected by the expansion of the springform-- ing the barrel, and thesprings 25 prevent a too violent action onrelease by holding the wedge blocks. Y 4

In the construction illustrated in Fig. 6

. wedge faces ofthe shoes contact with the the wedge blocks, wedge shoesand barrel may be as shown in the form already described. The shell,however, consists ofa pair of longitudinally continuous sections 28, 29cooperating with both sets of wedge elements and not being provided witha transverse web. The central springs 30 react directly between the twosets ofwedge shoes.

The action of the gear when made this form will be the same as intheform of'Fig. 1 except. that upon release the shell is re.-

' stored only by the frictional action and it may never return to thecentral position shown in 'Fig. 6. The efliciency of the gear, however,will not be in any wise diminished because of the floating character ofthe shell. \Vhile preferred for-ms of construction are .shown variouschanges in detail may be shaped wedge shoes inclosed within each end ofthe shell, spring means resisting the relative approach of the two setsof shoes, wedge blocks cooperating with each set of shoes, and followersfor advancing the blocks and longitudinally compressing the barrel.

- 2. In a draft gear, in combination, a barrel formed of a helicalspring, alongitudinally divided shell inclosed within and frictionallyengaging the barrel, a of sector; shaped wedge shoes inclosed wlthm eachend of the shell, spring means resisting the relative approach of thetwo sets of shoes, wedge blocks cooperating with each set' of shoes andhaving laterally extending flanges engaging the ends of the barrel, and'followers for advancingthe blocks and longitudinallycompressing thebarrel. I

3. In -a draft gear, in combination, a barrelformed of a helical spring,a longitudi-.

nally divided shell inclosed within and frictionally engaging thebarre'l and having a transverse wall midway of it's ends, a set ofsector-shaped wedge shoes inclosed within each 'endof the shell, springsreacting between the shell wall and thetwo'sets of shoes,

wedge blocks co-operating with each .set of shoes and followers foradvancing the blocks and longitudinally compressing the barrel.

4. In a draft gear, incombination, a barrel formed of a helical spring,friction elements engaging the inner surface of the .bar-

rel, wedge means for forcing the friction elements agalnst the barrel,spring means resisting theadvance of the wedge elements,

and means for compressing thebarrel longitudinally.

5. In a draft gear, in combination, a barrel consisting of a helical:spring formed of a bar angular 1n CIOSS-SECUOIQOIIB face of the barconstituting the bore of the barrel, friction elements engaging theinner surface of the barrel, wedge means for forcing the frictionelements against the barrel, spring means resisting the advance of thewedge elements, and means for compressing the barrel longitudinally. I

In testimony whereof-I affix my signature,

LEWIS T. CANFIELD.

